Changing staircase after loft conversion

[Shlumaan]

Hi, we've just had a loft conversion done in our 1930s semi detached house, and had it signed off by building control. My wife and I suddenly had a change of heart with regards to the staircase which is typically plastered and unsightly, and instead we would like to have open rise stairs. We had a quote and are happy to invest in replacing the stairs. However I'd like to know if there are any issues in terms of fire regulations and building control as they've already signed it off. The stairs begin on the 1st floor landing where all bedrooms have fire doors installed and finish at the loft landing, where a fire door to the loft room exists. Any considerations we should be aware of before doing the job? Thanks